In order to collect blood, in general, a blood collecting device is used which collects blood into a blood bag (a blood collecting bag) from a blood collecting needle through a tube. The blood collecting device (a blood collecting instrument) disclosed in, for example, Patent Literature 1 is a conventionally known blood collecting device of this type.
The blood collecting device disclosed in Patent Literature 1 includes a blood collecting needle, a blood collecting bag (a bag set) storing blood collected through the blood collecting needle, a blood collecting tube (a first tube) that interconnects the blood collecting needle and the blood collecting bag together, a branched tube (a second tube) branched from the halfway of the blood collecting tube, an initially flowing out blood bag (inspection blood bag (sample porch)) communicated with the blood collecting tube through the branched tube, and a three-way cock (a valve). According to this blood collecting device, since blood may be possibly contaminated by bacteria in or under a skin, an initial flow of blood (initially flowing out blood) collected from a donor is collected (stored) in the initial blood flow bag before blood is collected from the donor (blood donor) in the blood collecting bag, i.e., before a real blood collection is performed. The collected initially flowing out blood is taken in a plurality of blood collection tubes and used for various inspections.
According to such a blood collecting device, the three-way cock can take following three states.
That is, a first state is that the upstream side of the blood collecting tube is communicated with the branched tube (see FIG. 2(a) of Patent Literature 1).
A second state is that the upstream side of the blood collecting tube is discontinued to the branched tube, and the upstream side of the blood collecting tube is communicated with the downstream side thereof (see FIG. 2(b) in Patent Literature 1).
A third state is that the upstream side of the blood collecting tube is discontinued to the downstream side thereof (see FIG. 2(c) of Patent Literature 1).
When the blood collecting device disclosed in Patent Literature 1 is used, first, the three-way cock is set to be in the first state, and in this state, initially flowing out blood is collected into the initially flowing out blood bag. Next, after the initial flow of blood (initially flowing out blood) is collected in the initially flowing out blood bag, the cock (knob) of the three-way cock is operated in order to have the three-way cock become in the second state, and in this state, a real blood collection is carried out. After the real blood collection, the cock of the three-way cock is operated and the three-way cock is caused to be in the third state.
As explained above, according to the blood collecting device of Patent Literature 1, when a process transitions to a real blood collection after the initially flowing out blood is collected, the upstream side of the blood collecting tube is discontinued to the branch tube, and the upstream side of the blood collecting tube is communicated with the downstream side thereof (the three-way cock is caused to be in the second state).
According to the blood collecting device of Patent Literature 1, however, it is not easy to figure out in which state from the first to third states the three-way cock is, so that, for example, at the time of collecting an initially flowing out blood in the initially flowing out blood bag, if the three-way cock is not in the first state and is already in the second state due to an artificial error (i.e., unintentionally), when it is not figured out and an initially flowing out blood is collected, the anticoagulant in the blood collecting bag is mixed in the initially flowing out blood, and the precision of inspection thereafter decreases. Also, since the initially flowing out blood does not enter the initially flowing out blood bag but enters the blood collecting bag, there is a possibility that blood used for blood transfusion is contaminated by bacteria. As explained above, according to the blood collecting device of Patent Literature 1, after the initially flowing out blood is collected, when a process is transitioned to a real blood collection with the three-way cock being in the second state, the three-way cock can be in the second state before such a transition, i.e., before the upstream side of the blood collecting tube is discontinued to the branch tube, the upstream side of the blood collecting tube may be communicated with the downstream side thereof, resulting in a difficulty of carrying out a correct operation mentioned above.
Patent Literature 1: Japan Patent Publication No. 2002-528159